Magnetoresistive read sensor

ABSTRACT

An improved magnetoresistive read sensor ( 100 ) and a method of fabricating magnetoresistive read sensor ( 100 ) that eliminates film removal is disclosed. The magnetoresistive sensor ( 100 ) is formed by positioning a first mask ( 128 ) on a gap layer ( 104 ) split into three regions due to subsequent layers. A first mask ( 128 ) is positioned on the central region of the gap layer ( 104 ) and a first hard-biasing material ( 106 ) is deposited onto the outside regions of the gap layer ( 104 ). The first mask ( 128 ) is removed and a magnetoresistive element ( 116 ) is deposited onto the outside regions of the first hard-biasing material ( 106 ) and the central region of gap layer ( 104 ), thereby forming an active region ( 122 ), a first passive region ( 124 ) and a second passive region ( 126 ) of the magnetoresistive sensor ( 100 ). A spacer layer ( 118 ) is deposited onto the magnetoresistive element ( 116 ) in all three regions and a soft adjacent layer ( 120 ) is deposited onto the spacer layer ( 118 ) in all three regions. A second mask ( 134 ) is positioned over the active region ( 122 ) of the sensor and a second hard-biasing material ( 110 ) is deposited onto the soft adjacent layer ( 120 ) in the first passive region ( 124 ) and the second passive region ( 126 ). The second mask ( 134 ) is removed and contacts ( 112, 114 ) are positioned onto the second hard- biasing material ( 110 ).

This Application claims the priority benefit of a Provisional U.S.patent Application having application Ser. No. 60/041,268, filed on Mar.18, 1997.

BACKGROUND OF THE INVENTION

The present invention relates generally to a magnetoresistive (MR)sensor. More specifically, the present invention relates to an MR readsensor and a method of fabricating the sensor that eliminates theremoval of film from the passive regions of the sensor and reduces thecoupling dependence between thin film layers.

Magnetoresistive (MR) sensors utilize an MR element to read magneticallyencoded information from a magnetic medium, such as a disc, by detectingmagnetic flux stored on the magnetic medium. An MR sensor must containboth longitudinal bias and transverse bias to maintain the sensor in itsoptimal operating range so that it can properly detect the magneticflux. The dual biasing is established through various combinations ofexchange or magnetostatic biasing schemes.

The three critical layers of an MR sensor are the MR element, a spacermaterial and a soft adjacent layer (SAL). The MR element hasmagnetoresistive properties and low resistivity and generates an outputvoltage when a sense current flows through the layer. The SAL is amagnetic bias layer with high resistivity. The SAL biases themagnetization of the MR element and establishes transverse biasing. Thespacer material has non-magnetic properties and high resistivity andfunctions as a spacer between the MR element and SAL. The spacermaterial helps break the exchange coupling between the MR element andthe SAL, which allows the magnetic layers to act as two distinct layers,rather than one strongly coupled layer. Hard-biasing material is placedon each end of the MR sensor, to establish longitudinal biasing and formtwo passive regions of the sensor. The space between the passive regionsmaintains the transverse biasing and is referred to as the active regionof the sensor.

MR elements can “fracture” into multiple magnetic domains when they areexposed to an external magnetic field. To maximize the stability andoutput of the MR sensor, it is desirable to maintain the MR element in asingle domain state. Three methods for maintaining the MR element in asingle domain state are magnetostatic coupling, ferromagnetic exchangecoupling and antiferromagnetic exchange coupling. Magnetostatic couplingis accomplished by positioning a permanent magnet adjacent to the MRelement. Exchange coupling is accomplished by depositing a ferromagneticor antiferromagnetic layer adjacent to the MR layer so that one of themagnetic lattices of the magnetic layer couples with the magneticlattice of the MR element layer to preserve the single domain state ofthe sensor.

In existing MR sensors, alignment tolerances between various thin filmlayers and MR sensor mask features are critical. The alignmenttolerances in many prior art MR sensor designs greatly increases thecomplexity of processing because critical geometries frequently requireadditional and/or more difficult processing steps. Additional processingsteps increase the variance and contamination of the various thin filmlayers.

For example, designs using continuous MR element and SAL films in boththe active and passive areas of the sensor are sensitive to theunderlayer of the film. In the passive region of the sensor, the SALfilm functions as the underlayer for hard-biasing Cobalt-based alloyfilms. Cobalt-based hard-biasing films are inherently sensitive to theunderlayer crystal texture and to the cleanness and roughness of theSAL/Cobalt-alloy film interface. Also in the passive region, theCobalt-alloy film functions as the underlayer for the MR element. The MRelement is sensitive to various factors such as the underlayer crystaltexture, cleanness and roughness of the Cobalt-alloy film/MR elementinterface. The dependence of one film to the other makes the processcontrol inherently difficult in fabricating this type of sensor.

In addition, processes involving reactive ion etching or ion millingoften require stopping within a very small tolerance, such as 50Angstroms. These processes leave the surface of the film layercompromised and affect the exchange coupling. The dependence of one filmto an adjacent film makes exchange coupling very critical and affectsthe overall stability of the MR sensor.

One method for simplifying the process of making an MR sensor is byutilizing an abutting magnetoresistive head. The abutted head appearssimple with respect to sensor fabrication. Essentially, a thin MR layerextends over the central active region and a hard-magnetic material isformed over the passive regions. The reliability of the sensor, however,is affected by the abutted junctions between the passive and activeregions, which introduce complications in the magnetic and electricalproperties at these junctions.

Therefore, there is a continuing need for an MR sensor that reduces thecoupling dependence of adjacent films and eliminates the process ofreactive ion etching or ion milling various layers, thus decreasing thevariance and contamination of thin film layers.

BRIEF SUMMARY OF THE INVENTION

The present invention is a magnetoresistive (MR) sensor that reduces theprocessing variance and contamination of films fabricated using separatefilm depositions. The method of the present invention eliminates theprocess of etching or ion milling various layers and thus no filmsurfaces are left compromised and the exchange coupling between variousfilm layers is enhanced. In addition, the critical layers, which includethe MR element, spacer layer and soft adjacent layer (SAL), aredeposited together which allows better control of the thicknesses andcoupling of the materials.

The method of making an MR sensor in accordance with the presentinvention comprises enclosing a tri-layer stack of films by twolongitudinal hard-biasing films. The tri-layer stack of films includesan MR layer, a spacer layer and a SAL layer. Fabrication of the sensorincludes positioning a first mask on a portion of a gap layer to cover acentral active region of the sensor, which leaves two outside regionsseparated by the central region. A first hard-biasing film is depositedonto the first mask and the outside regions of a gap layer. The firstmask is removed and the MR element is deposited onto the central regionof the gap layer and the hard-biasing materials, thereby forming twopassive regions of the sensor separated by an active region. The spacerlayer is deposited onto the MR element in all three regions and the SALis deposited onto the spacer layer in all three regions. A second maskis positioned over the active region of the sensor and a secondhard-biasing material is deposited onto the second mask and onto the SALin the passive regions of the sensor. The second mask is removed andcontacts are positioned onto the second hard-biasing material.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of a prior art magnetoresistive read sensorin which the spacer and soft adjacent layers are positioned only in thecentral active region.

FIGS. 2-9 are sectional views illustrating the process of forming an MRsensor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is a sectional view of the reader portion of prior artmagnetoresistive (MR) sensor 50. The sectional view shown in FIG. 1 istaken from a plane parallel to the air bearing surface of the sensor. Inother words, the air bearing surface of MR sensor 50 is parallel to theplane of the page.

MR sensor 50 is positioned on top of gap layer 52 and includes MRelement 54, spacer layer 56, soft adjacent layer (SAL) 58, and first andsecond permanent magnets or hard-biasing materials 60 and 62. MR element54 includes first passive region 54 a, second passive region 54 c, andactive region 54 b, which is positioned between passive regions 54 a and54 c. Hard-biasing material 60 is positioned at least partially on topof first passive region 54 a of MR element 54. Likewise, hard-biasingmaterial 62 is positioned at least partially on top of second passiveregion 54 c of MR element 54.

Active region 64 of MR sensor 50 is formed between hard-biasingmaterials 60 and 62 and includes active region 54 b of MR element 54,spacer layer 56, and SAL 58. First passive region 66 of MR sensor 50 isformed above first passive region 54 a of MR element 54. First passiveregion 66 includes the portion of MR element 54 located in first passiveregion 54 a and first hard- biasing material 60. Second passive region68 of MR sensor 50 is formed above second passive region 54 c of MRelement 54. Second passive region 68 includes the portion of MR element54 located in second passive region 54 c and second hard-biasingmaterial 62.

Spacer layer 56 is positioned between hard-biasing materials 60 and 62and on top of active region 54 a of MR element 54. SAL 58 is positionedon top of spacer layer 56 such that SAL 58 is also located betweenhard-biasing materials 60 and 62. Hard-biasing materials 60 and 62provide the boundaries of active region 64 and make contact with spacerlayer 56 and SAL 58. Hard- biasing materials 60 and 62 also define theboundaries of the active region 54 a of MR element 54.

During fabrication, prior art MR sensor 50 is subjected to variousprocess steps which increase the variance and tolerances of each filmlayer. Initially, MR element 54, spacer layer 56 and SAL 58 aredeposited in all three regions (active region 64 and passive regions 66and 68) of MR sensor 50. However, portions of spacer layer 56 and SAL 58are removed from passive regions 66 and 68. First, SAL 58 is subjectedto an ion-milling process to remove the portions of SAL 58 not coveredby a photoresist. Next, spacer layer 56 is subjected to a reactiveion-etch process to remove the portions of spacer layer 56 not coveredby a photoresist. In addition, MR element passive regions 54 a and 54 bare sputter-etched to remove a small portion of MR element 54 in orderto establish a clean surface or underlayer for later deposition ofhard-biasing materials 60 and 62. These processing steps are costly andmake it difficult to control the magnetic properties of hard-biasingfilms. Thus, fabrication of a sensor such as sensor 50 is costly and mayor may not be within predetermined tolerances.

FIGS. 2-9 illustrate a preferred process of forming MR sensor 100according to the present invention. FIGS. 2-9 show structures 102 a-102g at various phases of the fabrication of MR sensor 100, while FIG. 9shows completed MR sensor 100. The cross-sectional views of FIGS. 2-9are taken from a plane parallel to the air bearing surface of thesensor. In other words, as with FIG. 1, the air bearing surface of MRsensor 100 is in a plane parallel to the plane of the page.

As shown in FIG. 9, MR sensor 100 is positioned on top of gap layer 104,which is adjacent to bottom shield 103. MR sensor 100 includeshard-biasing material 106 (106 a, 106 c), tri-layer 108, secondhard-biasing material 110 (110 a, 110 c) and first and second contacts112 and 114. Tri-layer 108 comprises MR element 116, spacer layer 118and soft adjacent layer (SAL) 120. Active region 122 of MR sensor 100 isdefined by active regions 116 b, 118 b and 120 b of MR element 116,spacer layer 118 and SAL 120, respectively. First passive region 124 ofMR sensor 100 is defined by first passive regions 106 a, 114 a, 116 a,118 a and 110 a of first hard-biasing material 106, MR element 114,spacer layer 118 and second hard-biasing material 110, respectively, andfirst contact 112. Second passive region 126 of MR sensor 100 is definedby second passive regions 106 c, 114 c, 116 c, 118 c and 110 c of firsthard-biasing material 106, MR element 114, spacer layer 118 and secondhard-biasing material 110, respectively, and second contact 114. Inaddition, first mask 128, which includes photoresist 130 and PMGI 132,second mask 134, which includes photoresist 136 and PMGI 138, are usedto fabricate MR sensor 100.

As shown in FIG. 2, first mask 128 is positioned above the central areaof gap layer 104 to protect the central area from future processingsteps. In a preferred embodiment, first mask 128 includes photoresist130 and PMGI 132, but is not limited to this combination of materials.Gap layer 104 is positioned between bottom shield 103 and MR sensor 100,where bottom shield 103 and gap layer 104 have varying thicknesses. Gaplayer 104 is preferably made of a non-magnetic, insulating material withgood thermal properties.

As shown in FIG. 3, first hard-biasing material 106 is deposited overstructure 102 a, shown in FIG. 2. Due to the configuration of structure102 a, first hard-biasing material 106 forms three distinctsub-materials 106 a, 106 b, 106 c. First hard-biasing material 106 b isdeposited on top of mask 128, specifically first photoresist 130, andfirst hard-biasing materials 106 a and 106 c are deposited on top of gaplayer 104 on either side of first mask 128. First hard-biasing material106 is preferably formed from cobalt-based permanent magnet materials,but other materials can be used. The thickness at the outer edge ofmaterials 106 a and 106 c is preferably between 200 and 1000 Å.

As shown in FIG. 4, first mask 128 has been removed from structure 102 busing a lift-off process. The lift-off process removes hard-biasingmaterial 106 b and mask 128, including PMGI 132 and photoresist 130. Thecombination of PMGI and photoresist creates a pattern that provides good“lift-off” of photoresist 130 and any other materials above photoresist130.

In FIG. 5, the materials of tri-layer 108, comprising MR element 116,spacer layer 118 and SAL 120, are deposited on top of structure 102 c,shown in FIG. 4. Active region 122 is defined by the area of tri-layer108 which is built on top of the central area of gap layer 104, whichincludes the active regions 116 b, 118 b and 120 b of MR element 116,spacer layer 118 and SAL 120, respectively. Passive regions 124 and 126of MR sensor 100 are defined by the portions of tri-layer 108 which arebuilt on top of hard-biasing materials 106 a and 106 c. Thus, the edgesof hard-biasing materials 106 a and 106 c adjacent to the central areaof gap layer 104 define the central and passive areas of sensor 100.

The first layer of tri-layer 108 is MR element 116. MR element 116 isdeposited on top of the central area of gap layer 104 and on top offirst hard-biasing materials 106 a and 106 c. MR element 116 is, inpreferred embodiments, a layer of permalloy. Permalloy is a namecommonly used to identify any of a large number of highly magneticallypermeable alloys containing a combination of nickel (Ni) and iron (Fe).It must be noted that other magnetoresistive materials can be usedinstead of permalloy. In preferred embodiments, MR element 116 has aresistivity of less than 100 μΩ-cm and a thickness in the range of 25and 400 Å.

The second layer of tri-layer 108 is spacer layer 118. Spacer layer 118is deposited on top of MR element 116 in all three regions (116 a, 116b, 116 c). Spacer layer 118 is a non-magnetic layer of high resistivitymaterial which is positioned between SAL 120 and MR element 116 toprevent magnetic exchange coupling between these two layers. Theresistivity of spacer layer 118 is preferably substantially higher thanthat of MR element 116 so that the majority of the current flows throughactive region 116 a of MR element 116, and increases the output voltagesignal from MR element 116. In preferred embodiments, spacer layer 118is a layer of tantalum (Ta) having a resistivity of at least 100 μΩ-cmand a thickness of between 25 and 500 Å.

The third layer of tri-layer 108 is SAL 120. SAL 120 is deposited on topof spacer layer 118 in all three regions (118 a, 118 b, 118 c). SAL 120is preferably a layer of Sendust-type alloy which is made up ofapproximately 70 to 90% iron (Fe), up to 15% silicon (Si) and up to 15%aluminum (Al). Sendust-type alloys can also contain small amounts ofadditional elements, in dilute form, such as up to 5% titanium (Ti),chromium (Cr), vanadium (V), manganese (Mn), and/or zirconium (Zr), toname a few. The Sendust-type alloy forming SAL 120 can be formed in avariety of sputtering gases such as argon, neon, krypton, xenon andhelium. SAL 120 can also be a layer of various ferromagnetic materials,for example nickel-iron-rhodium (NiFeRh), nickel-iron-rhenium (NiFeRe),or nickel-iron-chromium (NiFeCr), to name an additional few. Inpreferred embodiments, SAL 120 has a resistivity of greater than 100μΩ-cm to reduce current flow through the layer. SAL 120 has a preferredthickness of between 25 and 1000 Å and a saturation inductance of atleast 3 kilo-Gauss to properly bias MR magnetic layer 116. In preferredembodiments, SAL 120 is a Sendust-type alloy, which provides a goodunderlayer for second hard-biasing material 110.

While FIGS. 5-9 show SAL 120 positioned on spacer 118 which ispositioned on MR element 116, it is understood the SAL 120 and MRelement 116 may be interchanged. It is only critical that spacer 118 bepositioned between MR element 116 and SAL 120.

In FIG. 6, second mask 134 is positioned over active region 122 ofstructure 102 e, shown in FIG. 5. Second mask 134 preferably includesphotoresist 136 and PMGI 138.

In FIG. 7, second hard-biasing material 110 is deposited over structure102 e, shown in FIG. 6. Due to the configuration of structure 102 e,second hard bias material 110 forms three distinct sub-materials 110 a,110 b, 110 c. Second hard-biasing material 110 b is deposited on top ofsecond mask 134 and second hard-biasing materials 110 a and 110 c aredeposited on top of tri-layer 108, more specifically SAL 120, over firstand second passive regions 120 a and 120 c of SAL 120. Hard-biasingmaterial 110 is preferably formed from cobalt-based permanent magnetmaterials, but other materials can be used. In preferred embodiments,the thickness of hard-biasing material 110 at the outer edge ofmaterials 110 a and 110 c is between 200 and 1000 Å.

In FIG. 8, second mask 134 is removed using a lift-off process. Thelift-off process removes photoresist 136 and PMGI 138. In addition,hard-biasing material 110 b is removed with second mask 134. Similar tofirst mask 128, the combination of PMGI and photoresist creates apattern which provides good “lift-off” of photoresist 136.

In FIG. 9, contacts 112 and 114 are deposited on top of passive regions110 a and 110 c of hard-biasing material 110. The contacts connect MRsensor 100 to external circuitry for current input.

In preferred embodiments, transverse biasing is desired in active region116 b of MR element 116 and longitudinal biasing is desired in first andsecond passive regions 116 a and 116 c of MR element 116. MR element 116is transverse biased when its magnetization vector is rotated usingsoft-film biasing, shunt biasing or any other compatible transverse biastechnique. Longitudinal biasing is established using longitudinalhard-biasing films, such as cobalt-platinum, which suppress multipledomain formation in MR elements.

When MR element 116 is deposited, it will naturally form magnetizationvector M along its long axis across the plane of the paper. Currentdensity vector J is formed in MR element 116 as current passes throughMR sensor 100 during operation. Current density vector J andmagnetization vector M initially point in the same direction. Whenmagnetization vector M and current density vector J form an angle ofapproximately 45 degrees, the resistance of MR element 116 will varynearly linearly with the magnitude of magnetic flux entering MR element116. Thus, transverse biasing of MR element 116 is desired to obtainoptimal conditions for sensing magnetic flux from a disc.

Magnetization vector M is rotated by forming SAL 120 above MR element116. The magnetic field of SAL 120 causes natural magnetization vector Mof MR element 116 to be rotated approximately 45 degrees with respect tothe direction of current density vector J. Spacer layer 118 is depositedbetween MR element 116 and SAL 120 to prevent magnetic exchange couplingbetween the layers, thereby permitting the rotation of magnetizationvector M.

First and second passive regions 116 a and 11 6 c of MR element 116 areinhibited from magnetic rotation by the high coercivity, lowpermeability of first hard-biasing materials 106 a and 106 c,respectively, through exchange coupling. The exchange coupling causeslongitudinal biasing or suppression of the magnetic rotation because thegeometries of MR element 116 and first hard- biasing material 106 align.Inhibiting the magnetic rotation allows very little magnetic flux intofirst and second passive regions 116 a and 116 c, which establishes awell defined reader track width and increases the absorption of fluxinto active region 116 b.

SAL 120 is located in all three regions of MR sensor 100, active region120 b and passive regions 120 a and 120 c, but only active region 120 bof SAL 120 is needed to transverse bias the active region 116 b of MRelement 116. Therefore, SAL is also longitudinally biased in passiveregions 120 a and 120 c using second hard-biasing material 110. Theexchange coupling between second hard-biasing material 110 and SAL 120suppresses the magnetic field in passive regions 120 a and 120 c of SAL120.

The amount and effectiveness of exchange coupling that exists betweenfirst and second hard-biasing materials 106 and 110 and MR element 116and SAL 120, respectively, depends upon a number of fabricationparameters. For instance, the material of MR element 116 or SAL 120, thematerial of hard-biasing materials 106 and 110, the thickness of MRelement 116 or SAL 120, the thickness of hard-biasing materials 106 and110 and the ratio between the thicknesses of materials all contribute tothe effectiveness of exchange coupling. Deposition parameters such assputtering pressure and temperature and post-deposition fabricationparameters such as ion-milling or etching also contribute to theeffectiveness of exchange coupling. In addition to thickness anddeposition parameters, the underlayer of each film affects exchangecoupling. Cobalt-based hard-biasing materials are inherently sensitiveto the underlayer crystal texture, cleanness and roughness of theinterfacing films. The dependence of one film to the other makesfabrication difficult.

The present invention eliminates post-deposition steps such as ionmilling or etching. Spacer layer 118 and SAL 120 are not removed fromfirst and second passive regions 124 and 126 of MR sensor 100. Thiseliminates the need to stop within very small tolerances and avoidsleaving the surface of film layers compromised. Therefore, betterexchange coupling can take place between layers without the need foradditional processing steps.

The underlayer of hard-biasing materials 106 and 110 and MR element 116are improved by taking advantage of the order in which the films aredeposited. A desirable underlayer, such as amorphous Sendust orchromium, is chosen to control the characteristics of hard-biasingmaterials 106 and 100 and MR element 116. For example, SAL 120 forms agood underlayer for second hard-biasing material 110 when SAL 120 ismade of a Sendust-type alloy.

MR elements can “fracture” into multiple magnetic domains when they areexposed to an external magnetic field. To maximize the MR sensor'soutput and stability, it is desirable to maintain the MR element in asingle domain state through exchange coupling or magnetostatic coupling.The magnetic field of the hard-biasing material should be large enoughto ensure a single domain configuration, yet small enough so as not tochange the linearity and signal amplitude of the resultant MR signal.

In operation, the air bearing surface of MR sensor 100 would bepositioned adjacent to a magnetic storage medium. The magnetic storagemedium is rotated so that the magnetic information located in thestorage medium passes by the active region of the MR sensor. A sensecurrent flows through MR element 116. It is desirous to have anappropriate amount of sense current flow through magnetic layer 116 ofMR sensor 100, in order to more effectively read information stored onthe magnetic storage medium. Once the sense current has flowed throughMR sensor 100, auxiliary circuitry manipulates the MR sensor output inorder to recover stored data from the magnetic storage medium.

Although the present invention has been described with reference topreferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. A magnetoresistive read sensor comprising: afirst hard-biasing film positioned on a first region and a third regionof a gap layer, wherein the first and third regions are separated by asecond region; a magnetoresistive element positioned on top of the firsthard-biasing film and on top of the second region of the gap layer,thereby forming a first and a second passive region of the sensorseparated by an active region; an unetched and unmilled spacer layerpositioned on top of the magnetoresistive element, which extends overthe active region and the first and second passive regions; an unetchedand unmilled soft adjacent layer positioned on top of the spacermaterial, which extends over the active region and the first and secondpassive regions, the soft adjacent layer establishing transverse biasingfor the magnetoresistive element; and a second hard-biasing filmpositioned on top of the first and second passive regions.
 2. Themagnetoresistive read sensor of claim 1 and further comprising aplurality of contacts positioned on top of the second hard-biasing film.3. The magnetoresistive read sensor of claim 1 wherein themagnetoresistive element is formed from a soft-magnetic material havinga resistivity less than 100 μΩ-cm.
 4. The magnetoresistive read sensorof claim 1 wherein the spacer material is formed from a non-magneticmaterial having a resistivity of at least 100 μΩ-cm.
 5. Themagnetoresistive read sensor of claim 1 wherein the soft adjacentmaterial is formed from a soft-magnetic material having a resistivity ofat least 100 μΩ-cm.
 6. A magnetoresistive read sensor assemblycomprising: a first hard-biasing film positioned oil a first region anda third region of a gap layer, wherein the first and third regions areseparated by a second region; a magnetoresistive layer, a spacer layerand a soft adjacent layer positioned on top of the first hard-biasingfilm and on top of the second region of the gap layer, thereby creatingan active region located above the gap layer and a first and a secondpassive region located above the hard-biasing film, wherein the spacerlayer is fabricated between the magnetoresistive layer and the softadjacent layer and has an essentially uniform thickness and composition,and wherein the soft adjacent layer has an essentially uniform thicknessand composition and establishes transverse biasing for themagnetoresistive element; and a second hard-biasing film positioned ontop of the soft adjacent layer in the first and second passive regions.7. The magnetoresistive read sensor of claim 6 and further comprising aplurality of contacts positioned on top of the second hard-biasing film.8. The magnetoresistive read sensor of claim 6 wherein themagnetoresistive element is formed from a soft-magnetic material havinga resistivity less than 100 μΩ-cm.
 9. The magnetoresistive read sensorof claim 6 wherein the spacer material is formed from a non-magneticmaterial having a resistivity of at least 100 μΩ-cm.
 10. Themagnetoresistive read sensor of claim 6 wherein the soft adjacent layeris formed from a soft-magnetic material with a resistivity of at least100 μΩ-cm.